y=√(arc sin(1/x^3))
所以
dy=1/2√(arc sin(1/x^3))*d(arc sin(1/x^3))
=1/2√(arc sin(1/x^3))*1/√(1-1/x^6) *d(x^(-3))
=1/2√(arc sin(1/x^3))*1/√(1-1/x^6) *(-3x^(-4))dx
=-3/2√(arc sin(1/x^3))*1/√(1-1/x^6) *(x^(-4))dx